ath5k: Simplify cw_min/max and AIFS configuration

Get rid of overly complicated cw_min/max and AIFS configuration:

* Validate values in ath5k_hw_set_tx_queueprops(), so we can use them directly
  without further checks or computation in ath5k_hw_reset_tx_queue().

* Simplifiy by using AR5K_TUNE_AIFS|CWMIN|CWMAX variables directly since we
  don't support XR or B channels. That way we can also remove
  AR5K_TXQ_USEDEFAULT and the confusing logic around it.

* Update data types: AIFS is u8, CW's are u16.

* Remove now unneeded variables in ath5k_hw.

Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 65 insertions, 65 deletions

diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
index 9475b2157f2..b96bb985b56 100644
--- a/drivers/net/wireless/ath/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
@@ -258,8 +258,6 @@
         (AR5K_INIT_PROG_IFS_TURBO)                                      \
 )
 
-/* token to use for aifs, cwmin, cwmax in MadWiFi */
-#define AR5K_TXQ_USEDEFAULT     ((u32) -1)
 
 /* GENERIC CHIPSET DEFINITIONS */
 
@@ -530,9 +528,9 @@ struct ath5k_txq_info {
         enum ath5k_tx_queue tqi_type;
         enum ath5k_tx_queue_subtype tqi_subtype;
         u16     tqi_flags;      /* Tx queue flags (see above) */
-        u32     tqi_aifs;       /* Arbitrated Interframe Space */
-        s32     tqi_cw_min;     /* Minimum Contention Window */
-        s32     tqi_cw_max;     /* Maximum Contention Window */
+        u8      tqi_aifs;       /* Arbitrated Interframe Space */
+        u16     tqi_cw_min;     /* Minimum Contention Window */
+        u16     tqi_cw_max;     /* Maximum Contention Window */
         u32     tqi_cbr_period; /* Constant bit rate period */
         u32     tqi_cbr_overflow_limit;
         u32     tqi_burst_time;
@@ -1044,9 +1042,6 @@ struct ath5k_hw {
 #define ah_ee_version           ah_capabilities.cap_eeprom.ee_version
 
         u32                     ah_atim_window;
-        u32                     ah_aifs;
-        u32                     ah_cw_min;
-        u32                     ah_cw_max;
         u32                     ah_limit_tx_retries;
         u8                      ah_coverage_class;
 
diff --git a/drivers/net/wireless/ath/ath5k/attach.c b/drivers/net/wireless/ath/ath5k/attach.c
index 20d178eabc9..6e02de311cd 100644
--- a/drivers/net/wireless/ath/ath5k/attach.c
+++ b/drivers/net/wireless/ath/ath5k/attach.c
@@ -119,8 +119,6 @@ int ath5k_hw_attach(struct ath5k_softc *sc)
         ah->ah_txpower.txp_tpc = AR5K_TUNE_TPC_TXPOWER;
         ah->ah_imr = 0;
         ah->ah_atim_window = 0;
-        ah->ah_aifs = AR5K_TUNE_AIFS;
-        ah->ah_cw_min = AR5K_TUNE_CWMIN;
         ah->ah_limit_tx_retries = AR5K_INIT_TX_RETRY;
         ah->ah_software_retry = false;
         ah->ah_ant_mode = AR5K_ANTMODE_DEFAULT;
diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index 3e5ed6c0c80..6bd8dd6f327 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -849,9 +849,11 @@ ath5k_txq_setup(struct ath5k_softc *sc,
         struct ath5k_txq *txq;
         struct ath5k_txq_info qi = {
                 .tqi_subtype = subtype,
-                .tqi_aifs = AR5K_TXQ_USEDEFAULT,
-                .tqi_cw_min = AR5K_TXQ_USEDEFAULT,
-                .tqi_cw_max = AR5K_TXQ_USEDEFAULT
+                /* XXX: default values not correct for B and XR channels,
+                 * but who cares? */
+                .tqi_aifs = AR5K_TUNE_AIFS,
+                .tqi_cw_min = AR5K_TUNE_CWMIN,
+                .tqi_cw_max = AR5K_TUNE_CWMAX
         };
         int qnum;
 
@@ -901,9 +903,11 @@ static int
 ath5k_beaconq_setup(struct ath5k_hw *ah)
 {
         struct ath5k_txq_info qi = {
-                .tqi_aifs = AR5K_TXQ_USEDEFAULT,
-                .tqi_cw_min = AR5K_TXQ_USEDEFAULT,
-                .tqi_cw_max = AR5K_TXQ_USEDEFAULT,
+                /* XXX: default values not correct for B and XR channels,
+                 * but who cares? */
+                .tqi_aifs = AR5K_TUNE_AIFS,
+                .tqi_cw_min = AR5K_TUNE_CWMIN,
+                .tqi_cw_max = AR5K_TUNE_CWMAX,
                 /* NB: for dynamic turbo, don't enable any other interrupts */
                 .tqi_flags = AR5K_TXQ_FLAG_TXDESCINT_ENABLE
         };
@@ -937,7 +941,7 @@ ath5k_beaconq_config(struct ath5k_softc *sc)
                  */
                 qi.tqi_aifs = 0;
                 qi.tqi_cw_min = 0;
-                qi.tqi_cw_max = 2 * ah->ah_cw_min;
+                qi.tqi_cw_max = 2 * AR5K_TUNE_CWMIN;
         }
 
         ATH5K_DBG(sc, ATH5K_DEBUG_BEACON,
diff --git a/drivers/net/wireless/ath/ath5k/qcu.c b/drivers/net/wireless/ath/ath5k/qcu.c
index 4186ff4c6e9..84c717ded1c 100644
--- a/drivers/net/wireless/ath/ath5k/qcu.c
+++ b/drivers/net/wireless/ath/ath5k/qcu.c
@@ -36,24 +36,58 @@ int ath5k_hw_get_tx_queueprops(struct ath5k_hw *ah, int queue,
 }
 
 /*
+ * Make sure cw is a power of 2 minus 1 and smaller than 1024
+ */
+static u16 ath5k_cw_validate(u16 cw_req)
+{
+        u32 cw = 1;
+        cw_req = min(cw_req, (u16)1023);
+
+        while (cw < cw_req)
+                cw = (cw << 1) | 1;
+
+        return cw;
+}
+
+/*
  * Set properties for a transmit queue
  */
 int ath5k_hw_set_tx_queueprops(struct ath5k_hw *ah, int queue,
-                                const struct ath5k_txq_info *queue_info)
+                                const struct ath5k_txq_info *qinfo)
 {
+        struct ath5k_txq_info *qi;
+
         AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
 
-        if (ah->ah_txq[queue].tqi_type == AR5K_TX_QUEUE_INACTIVE)
+        qi = &ah->ah_txq[queue];
+
+        if (qi->tqi_type == AR5K_TX_QUEUE_INACTIVE)
                 return -EIO;
 
-        memcpy(&ah->ah_txq[queue], queue_info, sizeof(struct ath5k_txq_info));
+        /* copy and validate values */
+        qi->tqi_type = qinfo->tqi_type;
+        qi->tqi_subtype = qinfo->tqi_subtype;
+        qi->tqi_flags = qinfo->tqi_flags;
+        /*
+         * According to the docs: Although the AIFS field is 8 bit wide,
+         * the maximum supported value is 0xFC. Setting it higher than that
+         * will cause the DCU to hang.
+         */
+        qi->tqi_aifs = min(qinfo->tqi_aifs, (u8)0xFC);
+        qi->tqi_cw_min = ath5k_cw_validate(qinfo->tqi_cw_min);
+        qi->tqi_cw_max = ath5k_cw_validate(qinfo->tqi_cw_max);
+        qi->tqi_cbr_period = qinfo->tqi_cbr_period;
+        qi->tqi_cbr_overflow_limit = qinfo->tqi_cbr_overflow_limit;
+        qi->tqi_burst_time = qinfo->tqi_burst_time;
+        qi->tqi_ready_time = qinfo->tqi_ready_time;
 
         /*XXX: Is this supported on 5210 ?*/
-        if ((queue_info->tqi_type == AR5K_TX_QUEUE_DATA &&
-                        ((queue_info->tqi_subtype == AR5K_WME_AC_VI) ||
-                        (queue_info->tqi_subtype == AR5K_WME_AC_VO))) ||
-                        queue_info->tqi_type == AR5K_TX_QUEUE_UAPSD)
-                ah->ah_txq[queue].tqi_flags |= AR5K_TXQ_FLAG_POST_FR_BKOFF_DIS;
+        /*XXX: Is this correct for AR5K_WME_AC_VI,VO ???*/
+        if ((qinfo->tqi_type == AR5K_TX_QUEUE_DATA &&
+                ((qinfo->tqi_subtype == AR5K_WME_AC_VI) ||
+                 (qinfo->tqi_subtype == AR5K_WME_AC_VO))) ||
+             qinfo->tqi_type == AR5K_TX_QUEUE_UAPSD)
+                qi->tqi_flags |= AR5K_TXQ_FLAG_POST_FR_BKOFF_DIS;
 
         return 0;
 }
@@ -186,7 +220,7 @@ void ath5k_hw_release_tx_queue(struct ath5k_hw *ah, unsigned int queue)
  */
 int ath5k_hw_reset_tx_queue(struct ath5k_hw *ah, unsigned int queue)
 {
-        u32 cw_min, cw_max, retry_lg, retry_sh;
+        u32 retry_lg, retry_sh;
         struct ath5k_txq_info *tq = &ah->ah_txq[queue];
 
         AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
@@ -217,14 +251,13 @@ int ath5k_hw_reset_tx_queue(struct ath5k_hw *ah, unsigned int queue)
                 /* Set IFS0 */
                 if (ah->ah_turbo) {
                          ath5k_hw_reg_write(ah, ((AR5K_INIT_SIFS_TURBO +
-                                (ah->ah_aifs + tq->tqi_aifs) *
-                                AR5K_INIT_SLOT_TIME_TURBO) <<
+                                tq->tqi_aifs * AR5K_INIT_SLOT_TIME_TURBO) <<
                                 AR5K_IFS0_DIFS_S) | AR5K_INIT_SIFS_TURBO,
                                 AR5K_IFS0);
                 } else {
                         ath5k_hw_reg_write(ah, ((AR5K_INIT_SIFS +
-                                (ah->ah_aifs + tq->tqi_aifs) *
-                                AR5K_INIT_SLOT_TIME) << AR5K_IFS0_DIFS_S) |
+                                tq->tqi_aifs * AR5K_INIT_SLOT_TIME) <<
+                                AR5K_IFS0_DIFS_S) |
                                 AR5K_INIT_SIFS, AR5K_IFS0);
                 }
 
@@ -248,35 +281,6 @@ int ath5k_hw_reset_tx_queue(struct ath5k_hw *ah, unsigned int queue)
         }
 
         /*
-         * Calculate cwmin/max by channel mode
-         */
-        cw_min = ah->ah_cw_min = AR5K_TUNE_CWMIN;
-        cw_max = ah->ah_cw_max = AR5K_TUNE_CWMAX;
-        ah->ah_aifs = AR5K_TUNE_AIFS;
-        /*XR is only supported on 5212*/
-        if (IS_CHAN_XR(ah->ah_current_channel) &&
-                        ah->ah_version == AR5K_AR5212) {
-                cw_min = ah->ah_cw_min = AR5K_TUNE_CWMIN_XR;
-                cw_max = ah->ah_cw_max = AR5K_TUNE_CWMAX_XR;
-                ah->ah_aifs = AR5K_TUNE_AIFS_XR;
-        /*B mode is not supported on 5210*/
-        } else if (IS_CHAN_B(ah->ah_current_channel) &&
-                        ah->ah_version != AR5K_AR5210) {
-                cw_min = ah->ah_cw_min = AR5K_TUNE_CWMIN_11B;
-                cw_max = ah->ah_cw_max = AR5K_TUNE_CWMAX_11B;
-                ah->ah_aifs = AR5K_TUNE_AIFS_11B;
-        }
-
-        cw_min = 1;
-        while (cw_min < ah->ah_cw_min)
-                cw_min = (cw_min << 1) | 1;
-
-        cw_min = tq->tqi_cw_min < 0 ? (cw_min >> (-tq->tqi_cw_min)) :
-                ((cw_min << tq->tqi_cw_min) + (1 << tq->tqi_cw_min) - 1);
-        cw_max = tq->tqi_cw_max < 0 ? (cw_max >> (-tq->tqi_cw_max)) :
-                ((cw_max << tq->tqi_cw_max) + (1 << tq->tqi_cw_max) - 1);
-
-        /*
          * Calculate and set retry limits
          */
         if (ah->ah_software_retry) {
@@ -292,7 +296,7 @@ int ath5k_hw_reset_tx_queue(struct ath5k_hw *ah, unsigned int queue)
         /*No QCU/DCU [5210]*/
         if (ah->ah_version == AR5K_AR5210) {
                 ath5k_hw_reg_write(ah,
-                        (cw_min << AR5K_NODCU_RETRY_LMT_CW_MIN_S)
+                        (tq->tqi_cw_min << AR5K_NODCU_RETRY_LMT_CW_MIN_S)
                         | AR5K_REG_SM(AR5K_INIT_SLG_RETRY,
                                 AR5K_NODCU_RETRY_LMT_SLG_RETRY)
                         | AR5K_REG_SM(AR5K_INIT_SSH_RETRY,
@@ -314,14 +318,13 @@ int ath5k_hw_reset_tx_queue(struct ath5k_hw *ah, unsigned int queue)
         /*===Rest is also for QCU/DCU only [5211+]===*/
 
                 /*
-                 * Set initial content window (cw_min/cw_max)
+                 * Set contention window (cw_min/cw_max)
                  * and arbitrated interframe space (aifs)...
                  */
                 ath5k_hw_reg_write(ah,
-                        AR5K_REG_SM(cw_min, AR5K_DCU_LCL_IFS_CW_MIN) |
-                        AR5K_REG_SM(cw_max, AR5K_DCU_LCL_IFS_CW_MAX) |
-                        AR5K_REG_SM(ah->ah_aifs + tq->tqi_aifs,
-                                AR5K_DCU_LCL_IFS_AIFS),
+                        AR5K_REG_SM(tq->tqi_cw_min, AR5K_DCU_LCL_IFS_CW_MIN) |
+                        AR5K_REG_SM(tq->tqi_cw_max, AR5K_DCU_LCL_IFS_CW_MAX) |
+                        AR5K_REG_SM(tq->tqi_aifs, AR5K_DCU_LCL_IFS_AIFS),
                         AR5K_QUEUE_DFS_LOCAL_IFS(queue));
 
                 /*